The invention relates to actuators and zone valves for heating systems.
Zone valves are often utilized in hydronic heating and cooling systems The zone valves isolate specific areas or "zones" of the system. Typically, each zone valve is controlled by a thermostat, which causes the valve to open and close to achieve desired temperature changes.
Conventional zone valves are typically actuated by either a heat motor or an electric motor. In valves with a heat motor as the actuator, an electrically heated element causes linear movement of an actuating element that, in turn, opens the valve. In valves with electric motors, the motor and associated gears rotate an arm within the valve. As the arm rotates, a rubber plunger at its end moves away from a seat, allowing liquid to flow around the plunger. The arm is rotated through an angle of only 20.degree. to 30.degree., leaving the plunger in the path of the flowing liquid.